funcall-stm-handler

Arguments:
slot-name stream &rest args

This macro is only valid within a with-stream-class form. The
slot-name argument names a slot in the stream
which is accessed very quickly. It is expected to contain a function
object, which is funcall'ed along with the stream
and the other args. The macro returns whatever
values the function returns. This macro is useful for read-like
operations, where the stream is the first argument of the function.

You must load the :iodefs module to use this
macro. Do that by evaluating (require :iodefs). (It
is not an error to evaluate that form if the module is already
loaded.) This macro is intended for implementing device-level
functionality and should not be used except for that purpose. See Simple-stream Description
in streams.htm for a description of the device-level.

See streams.htm for information on the
simple-streams implementation in Allegro CL.